.com/booktv. author an astrophysicist neil degrasse tyson on america's call for scientists and engineers. >> as nasa's future goes, so, too, is that of america. and if nasa is healthy, then you don't need a program to convince people that science and engineering is good to do. because they will see it writ large on the paper. there will be calls for engineers to help us go ice fishing on europa where there's an ocean of water that's been liquid for billions of years. we are going to dig through the swiss of mars and look for life. that would give me the best biologist. look at the nasa portfolio today. it's got biology, chemistry, physics, geology, aerospace engineers, mechanical engineers, electrical engineers, all the s.t.e.m. fields, science, technology, engineering and math, represented in the nasa portfolio. a healthy nasa pumps that but a healthy nasa is a flywheel that society casts for innovation. >> over the past 15 years booktv has aired over 40,000 programs about nonfiction books and authors. booktv every weekend on c-span2. >> taking a look at what's ahead this morning. aske..